1. Technical Field
The present disclosure relates to a light adjusting device and light adjusting method thereof, especially relates to a day/night switchable light adjusting device and light adjusting method thereof.
2. Description of Related Art
Melatonin is a kind of Hormone that exists in a human body. In the human body, Melatonin is produced by a pineal. Melatonin has great influence on a sleep/awake mode, a day/night adjusting mode or a season adjusting mode of a human. High quantity of Melatonin increases drowsiness, and low quantity of Melatonin influences excitation factor of a people.
The quantity of Melatonin is influenced by various factors. In a physiological cycle, the quantity of Melatonin is different in a day time and a night time. In a day time, the quantity of Melatonin is low. On the contrary, in a night time, the quantity of Melatonin is increased rapidly. Another factor that influences the quantity of Melatonin is related with a wavelength region and intensity of a light. It is known that a cyan region light (550 nm˜540 nm) and a blue region light (480 nm˜500 nm) will decrease the quantity of Melatonin.
However, in a daily life, a lighting device usually utilizes a white light source, which contains various wavelength regions, such as the cyan region light or the blue region light as described above. Therefore, the quantity of Melatonin will be decreased by the white light source. In some situations, reduction of the quantity of Melatonin has bad influence. For example, some night workers should keep awake in the night time. Thus a day/night switchable lighting device is necessary.